Linux Kernel  3.7.1
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dm-kcopyd.h
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1 /*
2  * Copyright (C) 2001 - 2003 Sistina Software
3  * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
4  *
5  * kcopyd provides a simple interface for copying an area of one
6  * block-device to one or more other block-devices, either synchronous
7  * or with an asynchronous completion notification.
8  *
9  * This file is released under the GPL.
10  */
11 
12 #ifndef _LINUX_DM_KCOPYD_H
13 #define _LINUX_DM_KCOPYD_H
14 
15 #ifdef __KERNEL__
16 
17 #include <linux/dm-io.h>
18 
19 /* FIXME: make this configurable */
20 #define DM_KCOPYD_MAX_REGIONS 8
21 
22 #define DM_KCOPYD_IGNORE_ERROR 1
23 
24 /*
25  * To use kcopyd you must first create a dm_kcopyd_client object.
26  */
27 struct dm_kcopyd_client;
30 
31 /*
32  * Submit a copy job to kcopyd. This is built on top of the
33  * previous three fns.
34  *
35  * read_err is a boolean,
36  * write_err is a bitset, with 1 bit for each destination region
37  */
38 typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
39  void *context);
40 
41 int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
42  unsigned num_dests, struct dm_io_region *dests,
43  unsigned flags, dm_kcopyd_notify_fn fn, void *context);
44 
45 /*
46  * Prepare a callback and submit it via the kcopyd thread.
47  *
48  * dm_kcopyd_prepare_callback allocates a callback structure and returns it.
49  * It must not be called from interrupt context.
50  * The returned value should be passed into dm_kcopyd_do_callback.
51  *
52  * dm_kcopyd_do_callback submits the callback.
53  * It may be called from interrupt context.
54  * The callback is issued from the kcopyd thread.
55  */
57  dm_kcopyd_notify_fn fn, void *context);
58 void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
59 
61  unsigned num_dests, struct dm_io_region *dests,
62  unsigned flags, dm_kcopyd_notify_fn fn, void *context);
63 
64 #endif /* __KERNEL__ */
65 #endif /* _LINUX_DM_KCOPYD_H */